v3.25.1
Stock-Based Compensation (Tables)
 3 Months Ended
Mar. 31, 2025
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Schedule of Share-Based Payment Award, Stock Options, Valuation Assumptions
The weighted average assumptions used in the Black-Scholes option pricing model for options granted in three months ended March 31, 2025 and 2024 are as follows:
Stock Option Award AssumptionsMarch 31, 2025March 31, 2024
Expected dividend yield—%—%
Expected life6.25 years6.25 years
Risk-free interest rate4.22%4.28%
Expected volatility42.33%40.17%
Tecogen  
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Schedule of Stock Option Activity
Stock option activity for the three months ended March 31, 2025 was as follows: 
Common Stock OptionsNumber of
Options		Exercise
Price
Per
Share		Weighted Average Exercise PriceWeighted
Average
Remaining
Life		Aggregate
Intrinsic
Value
Outstanding, December 31, 20242,752,962 $0.71—$3.93$1.14 6.70 years$1,348,684 
Granted
30,000 $2.14—$2.88$2.32 
Exercised
(35,000)$1.10$1.10 $49,175 
Outstanding, March 31 20252,747,962 $0.71—$3.93$1.16 6.48 years$3,234,426 
Exercisable, March 31, 20251,805,462 $1.26 $2,036,326 
Vested and expected to vest, March 31, 20252,606,587 $1.17  $3,054,711